Monday marked the last day of a week-long ceasefire in the war-weary Arab country.

The truce had been brokered by Russia and the United States. It ushered in several days of relative calm, including in Aleppo, which has been divided between government forces and militants. Late last week, however, violence began to creep back into the city when a US-led airstrike killed scores of Syrian soldiers who were engaged in fighting against the Takfiri terrorist groups in the eastern parts.

Hours after the expiration of the truce, the UN said one of its convoys carrying aid to the civilians trapped under militant control in Aleppo was hit by an airstrike near the city. The world body said the airstrike destroyed at least 18 of the 31 trucks. It was not immediately clear who was responsible for the strike.

A Syrian opposition group claimed the attack had killed 12 Red Crescent volunteers and drivers.

A damaged aid truck is seen on the side of the road in the town of Urm al-Kubra on the western outskirts of the northwestern Syrian city of Aleppo, September 20, 2016. (Photo by AFP)

The United Nations (UN)’s special envoy to Syria, Staffan de Mistura, reacted by saying, “Our outrage at this attack is enormous… the convoy was the outcome of a long process of permission and preparations to assist isolated civilians.”

UN suspension

Meanwhile, the UN announced on Tuesday that all aid shipments in Syria had been suspended following the Aleppo attack.

Red Cross also said on Tuesday that it could only confirm the death of one Syrian Red Crescent volunteer in the attack and that the death toll “could be less” than reported so far

Fighting also intensified in the militant-held eastern suburbs of the capital, Damascus.

The United States has said, though, that it was prepared to extend the truce deal. The Russian military has said that it would be meaningless for the Syrian army to be the sole party observing the ceasefire while being attacked by militants.

Militancy has been killing thousands and displacing millions throughout the Middle Eastern country since 2011 on the back of support by foreign governments who oppose Syrian President Bashar al-Assad